Heat pump system



May 6, 1941. l H. GIBSON HEAT PUMP SYSTEM Filed Aug. 24, 1939 2 Sheets-hut l Hl-:ATIMGT-TI|- THERMOSTAT HuMlolsTAT comme u 1 THERMOSTAT /38 7.9m /40 Inventor: Hal Gibson,

-lza Attorn ey.

May 6 1941 H.- GlBsoN 2,241,060

HEAT PUMP SYSTEM Filed Aug. 24; 1959 2 sheets-sheet 2 Figi.. /534 zia 23s. 'im

y @E uw 4 Hal Gibson, by A VMyw@ f His Attovney door air. is circulated over the heat exchangers I2 and Il by operation' of a fan Il driven by a suitable motor Il, it being discharged through a i duct Il outside the enclosure to be conditioned.

Referring now to Fig. 1 of the drawings, the 5 The-refrigerant within the exchangers Il and I l base load system comprises a compressor Il driven by a motor II and connected in a refrigerant circuit including an indoor heat exchanger I2 and a pair of outdoor heat exchangers I8 and Il. The heat exchanger I2 is arranged within a duct I5 provided with a fresh air inlet Il and a recirculated air inlet Ilycommunicating with the enclosure to be conditioned and passing through a wall^`ll of the enclosure. Air is circulated through the duct Il by operation of afan Il driven by a motor 20 and is discharged into the enclosure through a duct 2| passing through the wally Il.` Electrically operated .valves 22, 2l, 2l, and 2! are provided for selecting the 'direction of flow of refrigerant through the refrigerant circuit jof the heat pump. The'heat exchangers I2, Il,

and I4 are provided with thermostatic expansion valves 28,' 21, and 2l, respectively. which control the admission of refrigerant tothe exchangers when they operate asevaporators. The valve 2l is operable tocontrol the admission of refrigerant to the heat exchanger I2 when that heat exchanger is being employed' as an evaporator,

check valves il and 2| being provided to prevent 22, 2l, 2l, and 2l are biased to their closed positions by springs It. 31. Il.A and It, respectively( and areprovidd with solenoids Il, I2. Il. and Il, respectively, for opening the valves in opposition to the springs. .When it is desired to operate the heat exchanger I2 as a condenser to heat the air passing through the duct Il. the valves 22 and 2l are held open by operation of their respective solenoids and when it is desired to operate the heat exchanger I2 as an evaporator or cooling element to cool the air passing-through the duct Il. the valvesl 22 and 2l are held open by operation of their soienoids. Only one pair of valves flnaybeheldopenatetime.l

`Duringtheoperation of thebaseload system to'heat the air padng through theduct Il. refrigerant by the compressor Il, discharged t the outlet Il, through the valve 2l and a conduit l! into the heat exchanger A .I2 where it is cooled-bythe air passing throh the duct Il and is liquefied. The liquid refriger ant leaving the heat exchanger I2 flows through the by-pass connection Il, the check valve Il and y a conduit 4I, and thence through the check valves l2 and Il, scale traps Il and II. thexpansion valves 2 1 and 2l into the heat exchangers Il and Il acting as evaporators. The check valves 8l and Il are held closed to prevent the passage of refrigerant through the by-pass connections l2 and Il respectively. .The liquid refrigerant la admitted to the heat exchangers Il and/I4 by operation of the expansion valves 21 and 2l having thermostatic control bulbs Il and ll respectively secured to the outlets of the evaporator units Il r and Il. The heat exchangers Il and Il ,are arranged within a duct Il. and air from outside the enclosure to be conditioned. ma preferably out il is vaporized by the absorption of heat 'from the air passing through the duct It, and the vaporized refrigerant is returned to the compressor Il through a conduit Il, connection l2, valve 25, and suction connection Il of the compressor.

During very mild heating weather it may not be necessary to operate the base load system at maximum capacity, and provision is made for cutting of! a certain portion of the outdoor evaporatorvfor limiting the compressor load at auch times. An electrically operated valve Il is provided in the inlet conduit to the heat exchanger section Il which valve in the closed position will cause the refrigerant to be circulated only through the expansion valve 21 and the evaporator section Il, therebylimiting the condenser l head pressure and at the same time tending to give better temperature regulation. 'The valve l0 is normally biased to the closed position by a spring Il and operable to the open position by solenoid Il.

During the operation of the base load machine to cool the air passing through the duct Il, the

` valve 2| is closed in order to prevent the flow of refrigerant through the by-pass connection 4l. Liquid refrigerant from the scale trap is admitted to the heat exchanger I2 by operationuof the thermostatlc expansion valve 2l, the valve being provided with a thermostatic control bulb B1 seymired to the exchanger YI 2 near the discharge end thereof. The liquid" refrigerant within the heat exchanger I2 absorbs heat from the air passing through the duct Il and thereby cools the air. the refrigerant being vaporized and discharged from the heat exchanger through the` conduit Il from which it is returned to the compressor Il through the connection Il, valve 22 and suction connection Il.

Thebase load system just described is preferably of such capacity thaty it will furnish ample heat for the enclosure during seasons of mild outdoor temperatures. During such` time the storage system is shut down and is thrown into operation as the need for additional heating becomes apparent. such as upon a `predetermined lowering of the outdoor temperature. I

The refrigerating, machine of the storage systemislargelysimilartothatofthebaseload system, and includes a compressor Il driven by a motor 'II and connected in a refrigerant circuit including an indoor heat exchanger 'I2 and an outdoor heat exchanger". The heat exchanger l2 is arranged within the duct I I in a manner similar to the heat exchanger I 2. The electrically operated valves 14, 1l, 1l, and 'Il are provided for selecting the direction of flow of refrigerant -through the refrigerant circuit of the storage svstem. The heat exchangers 'I2 and." are provided with thermostatic expansion valves 1l and valve ld, and-into the heat exchanger lt acting exchanger 12 is being employed as a condenser7 Check valves 83 and 8l are provided to cooperate l0 with the thermostatic expansion valvev land automatically control the ow of refrigerant so that the valve 19 is effective-only when the heat exchanger 73 is being utilized as an evaporator. The electrically operated valves ld, l5, 1S', and ll are `hiased to their closed positions by springs t5, $6, 8l, and 88 respectively and are provided with solenoids 89, 90, gi, andai respectively for opening the valves in opposition to the springs. 'When it is desired to operate the heat exchanger 'l2 as a condenser to heat the air passing through the duct lo, the valves l5 and 'il are held open oy operation oi their respective solenoids and when it is desired to operate the heat exchanger 'l2 as an evaporator to 'cool the air passing through the duct rl the valves ld and l@ are held. open by operation of their solenoids. (only one 'pair oi these valves may be held open a time. The operation ol the storage system retrigern ating machine in circulating reirigeral t through the heat exchangers 'it and 'l ls substantially similarto the operation or the loaseload roachhle in both the heating and cooling cycles.- During the operation of the reirlgerating' machine of the V storage system to heat the air through 35 the'duct lo. refrigerant is kcomprasted 'oy the compressor ld, discharged through the outlet fili. the valve l5, connection conduit lill,4 and into the neat exchanger l'rvhere it ls cooled hy the air passing through the ductr lll and is liquefied. The liquid refrigerant leaving. the heat exchanger 'di flows through the icy-pass connection dil, the check valve t?, and conduit dl, throughl the check valve the scale trap Qd, the expansion as an evaporator. The chech valve dit is held closed to prevent the passage oi refrigerant through the bly-'pass connection@d The liould refrigerant is admitted tothe heat exchanger lt; by operation of the expansion valvellil having 5@ thermostatic control bulb loi secured to the outlet of the evaporator unit 13. 'The exchanger it is arranged within' a vduct itl and air lroru the outside of the enclosure to he conditioned,

and preferably outdoor air, is circulated over the heat exchanger 'i3 by .operation oil a fan ldd driven by a suitable motor 10d, it being discharged through a duct '|05 outside the enclosure tohe conditioned. The y refrigerant within the exchanger 'it is vaporized by the absorption of heat from the air passing through the duct it?, and. the vaporlzed refrigerant is returned to the comn presser l0 through a conduit IBB, valve "I'I, and the suction connection |01 of the compressor.

During the operation oi' the refrigerating machine of the storage system to cool the air passing through the duct I5, the valves wand i6 are opened land the refrigerant compressed Within the compressor 10 is discharged through the connection 93, the valve 16, connection-l00, conduit |06 into the heat exchanger 'I3 serving as a condenser. 'Ihe compressed refrigerant within the heat exchanger 13 is cooled and liquefied by GID the air passing through the duct |02. The liquid 7 Arefrigerant is' discharged through the by-pass 75 pump lill arranged in the conduit itil.

conduit 09 into the conduit 91 from whence it ilows through the check valve 8l, and the scale trapy |09. The check valve 02 is `closed in order to prevent the ow of refrigerant through the ity-pass connection 96.` Liquid refrigerant fromthe scale trap 109 is admitted to the heat exchanger 12 by operation of the thermostatic expansion valve 18, the valve being provided with a .thermostatlc control bulb H0 secured. to the exchanger 12 near the discharge end thereof. The liquidreirigerant Within the heat exchanger 12 absorbs heat from the air passing through the duct i5 and thereby cools the air, the refrigerant being vaporized and discharged from the heat exchanger through the conduit 35, valve 14, and suction connection 01 to thecompressor 10.

' ySince it is economically undesirable to provide reirigerating machines of such capacity as will g be sumcient for supplying the heating requirements ylor the enclosure during the occasional periods of extremelotv temperature, means are provided lor 7storing heat within a reservoir which stored heat is then utilized for assisting the heating operation of the refrigerating macl'ilues dining the periods ol abnormally low temperature. The heat storage reservoir ill is provided for containing any suitable heat stor-Y uue medium, such as water, which is connected icy conduits lill and' l lil with a second condenser or heat transiter unit lit adapted to be con-g riected to the compressor ld. il circulating pump lill drivenloy a suitable motor lll is arranged in the conduit lift. A reirigerantcoil Si@ arranged within the unit llo is connected at one end hy a conduit lll with the discharge connection il@ oi? the compressor lll, the other end off the coil llt heling connected by conduit 62d rrltli. the conduit lil. Arranged in the conduit il@ :lo an electrically operated valve lli to the opened position hy a spring i222 and adopted to te operated to the closed positioucloy the solenoid llt. il heat exchanger l2@ arranged within the duct it is connected to the reservoir ltd icy the conduits il@ and Gilt, the' circulation oi liquid hetween the reservoir lil and the exchanger llt being edected by the The pump l 2l is driven. leyes suitable motor l @il which lniturn is energized through the control system upon demand for heating from 'the storage reservoir.- Arranged within the conduit lilo supl plying liquid to the heat exchanger Ai261 is a. suitable auxiliary electric heater l2@ for the pur-i pose of supplying additional heat to the storage liquid.

ln order to properly humidity the air passing through the duct lo into the enclosure dui-ing the heating operation of the system, a water `pau E36 is provided in. the bottom oi the duct.'

Water is admitted .into the pan through a con duit it@ from a suitable sourceoi supply, the ilow being controlled icy a `valve Vitt normally biased to the closed position hy means of aA spring 934 and operable to the opened position by a solenoid W5. The Water Within the pan lll is preferably heated by means ci an electric heater l in order `to increase the absorption thereof by the air. A iioat G31' ls suitably arranged within the pan I3I and is adapted to close a switch ill for energizing the solenoid 835101' maintaining a predetermined level of water Within the pan. A second switch W2 is adapted to be controlled by the float 31 for deenerglzing the heater |36 in the event that the water within the pan falls to a predetermined erating machines and operates the valves for'.

the cooling cycle. When there is a demand for heating, the thermostat Il! takes over the control or the retrigerating machines and the valvesare set for the heating cycle. A humidostat I is 'also arranged within the enclosure for controlling the humidity of the air supplied to the enclosure. A plurality oi thermostats responsive to various limits of the outdoor temperature are arranged within the fresh air duct I! for controling various phases of the operation of the rei'rigerating machines, the purpose and functioning of which thermostats will be made clear as the description oi the control system proceeds...

Referring now to Fig. 2, the lcontrol i'or the i 'sir conditioning system wiii be desoribed. In

this diagram the saine reference characters will be used to identify corresponding electrically operated elements shown in the diagrammatic arrangement o! Fig. 1.

Poweris supplied to the' system from a suitable source 'of supply through the lines `III and I l2. To put the system into operation, the control switch Il is iirst closed, whichconnects relay |55 across the supply lines I5I, |52. As

relay |54 picks up, its contact arm |55 closes a circuit connecting the supply line |52 with thc.`

conductor Ill which with line |52 supplies power to the remainder of the system. The arm |51 of relay Ill simultaneously connects the main ian blower motor 2l across the lines |52, |55 to start circulation ot air through the duct I5. At the same time the primary winding of the transformer Ill is energized for supplying Power to the'heating thermostat I and Lalso the primary winding of the transformer |55 is energized ior Supplying P0wer to the cooling thermostat III.' 'Ihe heating control thermostat III comprises `a bimetaliic member |5I and a pair of fixed contacts Il! and |83. During the operation of the air conditioning system when there is a demand for heating. the bimetallic strip Illiwill bend to the right thereby completing an energizing circuit for the relay I, which circuit extends from the right-hand terminal of the secondaryv winding` of transi former through the conductor ICU, the contact III', thermostatic element IUI, the winding o! 4relay I, conductor I to the other terminal of the transformer secondary winding. As the relay I picks up, a holding circuit is established therefor through its arm |81 andlines III and III parallelling the thermostatelement III and tlxed contact 102. Another circuit is established @on the closureoi' the relay |84 for eilecting the o peningof the electrically operated valves 28 and 25 and for simultaneously starting'the fan I1 torcirculating xair-'through heat exchanger units |3\and Il oi' the base'load system" For convenience. the heat exchangers Il and I4 as well as the/heat exchanger 1I will be simply referred to as the. outdoor heat exchangers, while the various heat exchangers cr- 2,241,054) low level, which might occur upon the failure ranged within the duct I5 will be referred to as the indoor heat exchangers. The valve operating circuit extends from the supply line ill through the contact arm |1I of the relay III, line |12.' contact arm |13 oi' the normally closed relay |14, line |15, contact arm |16 of the normaily closed relay |11, line |18, the solenoids I2 and Il connected 'in parallel, to the other supply line |52. 'Ihe control circuit for the 'outdoor fan motor ,5l extends from the energleed line I1I through the connection Ill, the closed arm III oi' the relay .|11, line III, winding oi'y the relay I" to supply line |52. As relay III picks up, an energizing circuit is established for the motor 5l extending from the supply line Ill through line Ill, the arm of relay III, through motor 88 to the other supply line |52.

A predetermined time following the operation of, relayA |53, another circuit will be established ior connecting the base load system compressor motor II across the supply lines. This circuit extends from the energized line |15, connection IH, arm III of the relay |11, connection III,` line Il1. the arm4 Il l of relay |33 lthrough the winding of relay III Ato the other supply line III. The arm IUI of relay |83 is restrained against closure by a suitable time delay device |92 until a predetermined time following lthe pick-up ot the relay Ill. Upon the closure of the control relay III, acircuit is established for energizing the motor I which circuit extends from the sup- -ply line |58 through line |54, connection III, the arm I oi the relay ISI, the motor II to the other supply line I 52. The time delay in connecting the compressor motor II to the supply line is incorporated in order to insure that all liquid and las transients are smoothed out before the new cycle of operation occurs. Such transients are likely to occur when quick'switching from heating to coolingoperation is required. The com- Dressor will circulate refrigerant between `the indoor heat exchanger I2 acting as a condenser and the outdoor heat exchanger unit Il acting as an evaporator to pump heat from the outdoor atmosphere into the enclosure. During this time the valve Il is in its closed position so that only the outdoor heat exchanger unit Il is included in the refrigerant circuit. The base load refrigerating machine will continue in operation to pump heat from outdoors into the enclosure until the demand for heat thereby is satisfied. Upon such time the thermostatic element IBI of the' thermostat I 58 will move to the left to engage contact III, thereby short circulting the coil of the relay I causing it to drop out. As the arm I1I oi the relay I moves to the open circuit position, the solenoids Il and M will :be deenergized allowing the associated valves to return to .then-closed positions. Simultaneously the relay I" will be deenergized, thereby open circuiting the blower motor I8 as well as the compressor motor I I.

Now assume that the base load system is in operation as described above and that the outdoor .temperature falls to a iirst predetermined iow velue, suon es 4o deg. F. A thermostat iu arranged within the fresh air duct I 5 moves to its closed circuit position, thereby completlngan energzing circuit through the line I Il for `the solenoid Il for operating the valve 5D to the line opened position. 'I'he outdoor heat exchanger unit Il will thereby be connected in parallel with the unit Il.v The evaporator capacity is corre- .y spondingly increased and a correspondingly greater amount ot vheat will be pumped into the enclosure `for meeting the increased requirement.

` of the heat storage system is maintained in op- 2,241,oeo

reservoir thermostat |98, line |99, the solenoid 92 of valve 11, the normally closed arm 20| of the relay |11, line 202 -to the other supply line |52. The circuit for operating valve |2| extends from the energized line |99, through connection 203, .the normally closed arm 204 of the relay 205, connection 206, the solenoid |23 for opening valve |2|, line 209 to the other supply line `|52. A circuit is established for putting into opration the heat storage refrigerating machine which circuit extends from the energized line 206 through theL line 2| l, the control relay 2|2 to the supply line |52. As relay 2 2 picks up, the motor |`|1 coupled for driving the heat storage liquid circulating vpum-p H6 is connected directly across the supply lines |56 and |52 through the line 2|3, arm 2|5 of relay 2 2, and line 2 4. A second circuit is established by relay 2|2 extending from the supply line |56 through the thermostat |95, thermostat |98,line E99, line 293, the normally closed arm 2 9 of the relay 205, arm 258 of the relay |11, arm 2|9 or" the closed relay lifline 229, the winding of control relay 222i, to the other supply line |52. As relay 22| picks up, a circuit is closed for en- 35 ergizing the motor Mill coupled for driving` the fan |53 of the outdoor heat exchanger il. This circuit extends from the supply line E56 through lines MB, 222, 223, the arm 925 of the relay 22| through the motor iiii to the other supply line A predetermined time following the picttup oi relay 22|', a second arm 225 thereof closes another circuit for eiecting the energization ci the compressor motor lli. This circuit extends from the supply line |59 through thermostats |95 and |98, through'lines |99, 209, arm 2|6 of relay 205, arm 2|8 of relay |11, the closed arm 2l9 of relay 2|2, line 226, the arm 225 of relay 22|, the winding of the control relay 229, to the other supply line` |52. The time delay operation of the arm 225 is effected lby a suitable restraining device 4indicated at 230. As relay 229 picks up, an energizing circuit -is established from the supply line |56 through lines 2|3, 222, for the compressor motor 1| Vof the heat storage reirigerating machine. As longv as the outdoor temperature remains below 40 deg. F., and above :a second lower predetermined value, the refrigerating machine eration until the temperature of the heat storage 60 medium reaches an' appropriate value determined by the discharge temperature of the compressor,

for example, 120 deg. F. The reservoir thermostat |99 may be adi-usted to open at this value. As the temperature of either the outdoor atmosphere or the liquid within the storage reservoir is increased above .these predetermined values, the

corresponding thermostat, |95 or |99, will open its contacts rto effect the deenergization of the heat storage refrigerating machine and to eiect llthe return of the valves 11 and 2| to the normally cl'osed-.positiom When the outdoor temperature falls to a second lower predetermined value, for example, to 26 deg. F., the base load system may no longer be able to supply the required amount of -heat for the enclosure, The refrigerating machine of the vheat storage system may then be connected for operating parallel with the base load system for direct heating of the enclosure. When this condition oi.' outdoor temperature occurs, a second thermostat 24.0 arranged within the fresh air duct I6 closes its contacts to complete a circuit extending from the supply line |56 through the line 24|, the solenoid of the relay 205, lines 243, 244 tothe other supply line |52. When'the relay 205 picks up, the arm .204 thereof raises to break the4 energizing circuit for the solenoid |23, allowing valve |2| to move to the closed position under the force of its biasing spring. lI 'he 'operating solenoid 92 of valve 11 will now be energized through a circuit extending from the supply line |56 through line 239, the arm 245 of the relay 205, line |99, the solenoid 92, through the arm 20| of relay |11, andline 202 to the supply line i52. Simultaneously, the operating solenoid of valve 15 will be energized to move that-valve to the opened position, the energizing circuit extending from the supply line |56 through the line 2|3, the solenoid 90, arm 246 of the relay 205, line 241, to line y|99, through the arm 20| of relay |11, line 202 to the supply line |52. It will be noted that as the arm 204 of the relay 205 moved to the open circuit position, the energizing winding of relay 2|2 was thereby open circuited causing it to drop out and deenergize the pump motor il. Anotherv circuit is established, however, for maintaining the operation of the ian motor |04 and the cornpressor motor li. This circuit extends 4from the supply line |56 through lines 2 I3, 258, the arm 249 ci the relay 205, lines 259, 25|, 229 through the winding of relay 222| to the other supply line |522. Below the value for which the thermostat 2li@ is set, the heat storage refrigerating machine will run continuously to supply heat directly to the enclosure, while the base load system continues to operate, as before, under the control of the heating thermostat |39 aspreviously described to regulate the enclosure temperature.

`Upon the occurrence of a condition of extremely low outdoor temperature, lfor example, such as 5 degrees F., a third thermostat 255, arranged within the fresh air duct I6, moves to its circuit closing position, completing an energizing circuit for the winding 251 of relay |14 through lines 256, and 244. As the relay |14 picks up, the base load j system is thrown directly across the line for continuous operation by the opening of arm |13 and 'the closing of arm 253, while the heating thermostat-V |39 is connected for controlling the pump |21 for circulating heat storage liquid through the Y heat exchanger |24. 'The latter circuit extends from the supply line |56, the arm |1| of the ther.-

' mostat relay |64, through lines |12, 260, arm 26| of relay |14, line 262 to the'winding of relay 263, to the other supply line |52. As the relay 263 picksl up, an energizing circuit is completed through lines y264, 266 for the 'motor |29 coupled for driving the pump |21. A parallel circuitis also established extending from the energized line 262 through line 261 for the relay 268 which com-- nects the heaterl- |29 across the supply lines throughl lines 264, 299 and 212. The heater |29f is of such capacity that it will/raise the tempera-f ture of the water Abeing circulated through the heat exchanger |24 to a suitable higher tempera-- ture, for example, approximately 160 deg, F. Below 5 deg. F. the two refrigerating machines, that is, of the base load system and of the heat storage system, operate continuously to pump heat the indoor heat exchanger I2. f

fromoutdoors in to the enclosure. The temperature within the enclosure is regulatedby the heating thermostat |55 controlling the l,on and on operation of the heat storage circulating pump |21 and the electric heater |25.

Following through the operation of the system for a reversal of the sequence Just described, as would occur during a rising'condition of outdoor temperature, the thermostat 255 will i'lrst open its contacts upon the outdoor temperature rising winding 251 of relay |14 will be broken, causing that relay to drop out thereby disconnecting the heat storage circulating pump motor |25 and the electric heater |25 from the control of the heat-- ing thermostat |55 and connecting the thermostat |55 for controlling the periodic operation of the base load system as previously described. Upon further increase in outdoor temperature, for example, to a value above 26 deg. F., the thermostat 255 will open its contacts thereby breaking the energizing circuit for the winding 252 of relay 255. As that relay drops out, the refrigerating machine of the heat storage system will `be disconnected from the heat exchanger 12 'and will be operated continuously to pump heat into the storage reservoir I I2. 'Ihe base load system then will operate alone to supply the heating requirements for the enclosure. Upon a'further increase |11,YV which completes an energizing circuit ex. tending from the supply line I 55, the line |55, line |55, arm 555 of the relay |11, lines |51, |55, |52, through the winding of the relay |55 to the 5 other supply line |52. As the relay |55 picks up,

the fan motor 55 ls started followed a predetermined time later by the 'energization of the compressor motor Il. Since the duct thermostat |55 will now be in its open circuit position, the solel noid 55 will be deenergized and valve 55 will be above deg. F. The energizing circuit for the in its closed position. Both outdoor units l5 and I5 of the base load system will function as condensers, however, since they will discharge through the by-passes 52 and 55. Solenoid |25 15 and relay 2 l2 are deenergized due to the opened condition of the thermostat |55 so that the valve |2| and the circulating pump motor ||1 of the heat storage system are inoperative during the cooling cycle.- The refrigerating machine of the base storage system, however, will be operated in parallel with the machine of the base load system under the control of the cooling thermostat |55 through the relay |11. Upon the closure of the contact arm 55| of relay |11, a circuit will be established extending from the supply line |55,

through lines 2|5, 222, contact arm 55| of relay |11, lines 25|, 225, 225, the winding of relay 22|, to the other supply line |52. lAs the relay 22| picks up, an energizing circuit will beestablished in outdoor temperature, mr exmple, above 40, 3o for the blower fan motor |55 followed a prededeg. F.. the thermostat |55 will open its contacts' thereby shutting down the heat storage machine and breaking the circuit for solenoid 55, causing valve 55 to move toits closed position. The evaporator section I5 of the outdoor heat exchanger will be thus disconnected from the refrigerant circuit of the base load system, since ample heat tor satisfying the requirements of the enclosure may be transferred from the outdoor' unit |5 to- Upon a predetermined rise of the lenclosur temperature above the normal operating range of the heating thermostat |55, for example, 5 degrees, the cooling thermostat |55Y comes into operation. 'I'he cooling thermostat |55 is similar to the heating thermostat |55 and comprises a thermostatic element 255 Aand a pair of fixed contacts 25| and 252. element 255 will bend to the right engaging with contact 252 thereby completing an energizing circuit for the winding of relay 255, which circuit extends from the right-hand terminal of the secondary winding of transformer |55 through the line 255, the contact 252, thermal element 255, line 255, the relay 255, line 255, to the other terminal of the transformer secondary winding. As

therefor Athrough lines 251 and 255 and arm, 255 hrall th thermal element 255'and nxecl p en e A ,.0 tion or the air duct il. 'nue circuit extends from contact 252. Another circuit established by re` lay'255 forenergizing the winding o! relay |11 eraan; solenoid` 4|, u, n, and si er valine z,

2L-15, and 15 respectively. 'I 'he energization of-A the base load refrigerating machine-will be e1'- 40 ranged within the enclosure.

Upon a call for cooling, the,

35 erated simultaneously and in parallel under the control of the cooling thermostat |55.

When the system is operating for heating, the humidity of the air supplied to the enclosure is controlled by the humldostat |55 suitably ar- The humidostat comprises a humidity responsive element 555 and a pair/of oppositely arranged fixed contacts 555 and 551. When the humidity of the air drops below a. predetermined value, the element 555 will be actuated to the right engaging with the hxed contact 551, thereby completing an energizing circuit for the relay 555, the circuit extending from the right-hand terminal of the secondary winding of the transformer 555 through line 5|5.

fixed contact 551, element 555, line 5| I, winding loi' the relay 555, line 5|2 to the other terminal v*of the transformer secondary winding. As the relay 555 picks up, a holding circuit is established therefor through the lines 5|5 and 5|5 and contact arm 5|5 of the relay 555 paralleling the element 555 and contact 551. As the relay 555 picks up, an energizing circuit is also established for thehumidinerheater |55 located in thebottom of the'water pan |5| arranged in the lower porthe supply line .|55 through line 5|5, heater |55. protective switch |52, line 5|5, arm 5|5 of the relay 555, line 525 tothe other supply line |52. Another circuit is established parallel with the heater circuit for energizing thesolenold |55 of the water supply valve |55 under the control of the float |51 arranged within the'water pan |5|. This circuit may betraced from the supply line |55, through line 52|, solenoid winding |55, float switch MI, line 525, contact arm 5|5 ,of the relay feeted by the creeeren: the lcui nto: the relay. 1s solenoid In for opening the valve m to una more water to the pan. Upon the .reestablishment oi the predetermined level L water, the float switch |4`|\ will be opened deenergizing the solenoid |35, permitting the valve |33 tol be actuated to its closed position.- In the event of.

failure of water supply, and should the water level in the pan |3|\ drop below a second predetermined point, for example, so as to uncover the humidifier heater, the second switchV |42 will be will be in operation only when the system is inheating operation or when the relayl |11 is in the deenergized condition. The energizing circuit for the transformer 309 is completed through the contact arm 326 of the relay |11, in its lower position. When the system is conditioned for cooling, that is, upon the control of the system being taken over by the cooling thermostat |30, the relay |11 will be actuated to its upper position causing the contact arm 326 to open the circuit for the transformer 309 thereby 'deenergizing the humidifier apparatus. l

Although I have described my invention in connection with a refrigerating machine for conditioning the air within an enclosure,kother uses will readily be apparent to those skilled in' the art. El'. do not, therefore, desire my invention to be limited to the particular construction shown and described, and I intend in the appended claims to cover all modifications falling within spirit and scope of my invention. "that claim as new and desire-to secureby Patent oi the United States, is:

i.. apparatus for heating the air within an encicsure including a duct, a reversed cycle refrigerating' machine comprising a compressor, a' condenser, and an evaporator, said condenser being arranged Within said air duct for heating air circulated therethrough, means for circulating air through. said duct and into said enclosure, said evaporator comprising a pair of parallel connected heat exchanger units arranged outside of said enclosure and said duct, normally closed valve means for excluding one of said heatV exchanger units from the refrigerant circuit, and means responsive to the temperature of, air to be heated for opening said valve.

2. Apparatus for heating they air within an enclosure including a duct, a refrigerating machine .comprising a compressor, a condenser and an evaporator, said condenser being arranged Within said duct for heating the air for said enclosure, means for circulating air through said duct and .into said enclosure, said evaporator comprising a plurality of heat yexchanger units adapted to be connected in the refrigerant circuit for parallel operation, and means responsiveto the temperature of air to be heated for controlling the inclusion of one of theiheat exchanger units in -the refrigerant circuit.

3. Apparatus for heating the air within an'enclosure including a duct. a refrigerating machine comprising a compressor, a condenser, and

an'evaporator, said condenser being arranged within said; duct, means for circulating air through said duct and into said enclosure, said evaporator comprising a plurality of heat exchanger units adapted to be connected in the re- A Afrigerant circuit for parallel operation, said 'Y evaporator being arranged outside of said enchanger units from the refrigerant circuit, and means responsive to predetermined temperature limits of air to be heated for opening said valves for increasing the heating capacity of said refrigerating machine.

d. In combination with a reversed cycle refrigerating machine comprising a compressor, a

iirst and a secod evaporator-condenser sections,

said second evaporator-condenser section comprising a plurality of parallel connected heat exchange units, valve means for selectively controlling the flow of refrigerant to certain of said units when operating as evaporators, means responsive to predetermined conditions for adjustnected to said compressor for heatingA the liquid in said reservoir, means responsive to, one predetermined outdoor temperature for connecting said compressor to said second condenserfor heating the liquid in said storage reservoir, and means responsive to a second lower' predetermined outdoor temperature for transferring the connection of said compressor from said second condenser to said iirst condenser for directly heating air for said enclosure.

d. Apparatus for heating the air Within an enclosure including a duct, means for circulating air through said duct, a rerigerating machine comprising a compressor, a condenser, and an evaporator, said condenser. being arranged within said duct for heating the ,air circulated therethrough; a reservoir containing a heat storage liquid, a second condenser adaptedto be con-1 nected to said compressor for heating the liquid in said storage reservoir to a predetermined ternperature, a heat exchanger arranged within said V,ed vfrom said reservoir through said heat exchangclosure Aand saidfduct, normally closed valve meansforgexcluding vcertain oi' said heat ex- 75 duct, means for circulating the liquid. from said storagereservoir through said heat exchanger, and means for heating the liquid being circulater to a second higher4 predetermined temperature.-

7. Apparatus fory heating the air within an enclosure including a duct, a refrigerating machine comprising a compressor, a condenser, and an evaporator, said condenser being arranged within said duct for heating the air circulated therethrough, a reservoir containing a. heat storage liquid, a second condenser adapted to be connected to said 'compressor for heating the liquid in said storage reservoir, a heat exchanger arranged in said duct, means for circulating the liquid from said storage reservoir through said heat exchanger, means for heating the storage liquid circulated through said heat exchanger to a second higher predetermined temperature. means responsive to a predetermined outdoor temperature for operating said refrigeratin'g machine for pumping heat from outdoors into said storage reservoinmeans responsive to a predetermined temperature within said enclosure for operating said refrigerating` machine for pumping heat from outdoors to said iirst condenser, and means responsive yto a second lower predetermined outdoor temperature ior simultaneously energizing said liquid circulating means and said heating means.

8. Apparatus for heating the air within an enclosure including a duct, means i'or circulating air through said duct. `a reirigerating machine comprising a compressor, a iirst condenser, and an evaporator, said iirst condenser being arranged within said duct for heating the air circulated therethrough, a reservoir containing a heat storage liquid, a second condenser adapted to be connected to said compressor for heating the liquid in said reservoir, means responsive to a first predetermined outdoor temperature for connecting said compressor to said second condenser for heating the liquid in said storage reservoir, means responsive to a second lower predetermined outdoor temperature for connecting said compressor to said ilrst condenser for directly heating the air oi said enclosure,` and means responsive to afthird lower predetermined outdoor temperature for transferring the heat from said storage reservoir to the air 'for said enclosure.

. 9. Apparatus for heating the air within an enclosure including a duct, means for circulating air through said duct, a iirst heat pump having a condenser arranged in said duct for heating the air circulated through said duct, means responsive tothe temperature within said enclosure for controlling the operation oi' said iirst heat pump, a second -heat pump having a condenser arranged within said duct for assisting said first condenser in heatingthe air circulated through said duct, a reservoir containing a heat storage liquid, a second condenser for said second heat pump for supplying heat to the liquid in said storage reservoir, and means responsive to outdoor temperature for selectively connecting said second heat pump either to said first condenser or to said second condenser.

10. Apparatus for heating the air within an enclosure including a duct, means for circulating air through said duct, a iirst heat pump having a condenser arranged in said duct for heating the air circulated therethrough, a second heat pump having a first condenser arranged in said duct, a reservoir containing a heat storage liquid, a second condenser for said second heatpump for heating the liquid ot said storage reservoir, a heat exchanger arranged in said duct, means for circulating the liquid from said storage reservoir through said heat exchanger, means responsive to the temperature within said enclosure for conjtrolling the operation of said first heat pump for maintaining the temperature within said enclosure within predetermined limits, and means responsive to predetermined ranges ot outdoor temperature for selectively controlling the operation ot` said second heat pump relative to said nrst and said second condensers and for conditioning said liquid circulating means for control by said enclosure temperature responsive means.

l1. Apparatus for heating the air within an enclosure including a first heat pump having aV condenser arranged in said duct for heating .the air circulated through said duct. a second heat pump having a rst condenser arranged in said duct, a reservoir containing a heat storage liquid,

a secondvcondenser for said second heat pump tor supplying heat to said reservoir, a heat exchanger arranged .in said duct, means for` circulating the liquid from said storage reservoir through said heat exchanger, responsiveyto a predetemperature within saidf'encloeure Ior 'air to be heated for controlling said rst heat pump for heating the air-Iorsaid enclosure, means responsive to a predetermined outdoor temperature for controlling said second heat pump for heating the liquid in said storag'ereservoir, means responsive to a ysecond lower predetermined outdoor temperature for controlling said second heat pump for supplying heat to said first condenser for heating the air within said duct, means responsive to a third lower predetermined outdoor temperature for initiating the operation oi said heat storage liquid circulating means.

12. Apparatus for heating the air within an.

enclosure including a duct, means-for circulating air through said duct, a plurality of reversed cycle refrigerating machines each comprising a compressor, a condenser, and 'an evaporator, said condensers of each machine being arranged within said duct for heating the air circulated therethrough, means responsive to the enclosure temperature, one oi said reirigerating machines being adapted to be normally controlled by said enclosure temperature responsive means, a reservoir containing a heat storage liquid, a second condenser adapted to be connected to the compressor of one of the other refrigerating machines for heating the liquid in said reservoir, means responsive to one predetermined outdoor temperature for connecting said other compressor to said second condenser, means responsive to relatively lower predetermined outdoor temperatures for conditioning all of said refrigerating machines for directly heating the air for said enclosure, means for transferring the heat from said storage reservoir to the air circulated through said duct including a heat exchanger and a pump, means responsive to a further relatively lower predetermined outdoor temperature for conditioning said pump for control by said enclosure temperature responsive means.

13. Apparatus for conditioning the air within an enclosure including a duct, means for circulating air through said duct, a plurality of reversed cycle rei'rigeratingmachines each having a heat exchanger arranged within said duct and a heat exchanger arranged externally oi' said duct and oi: said enclosure, means responsive to the temperature within said enclosure for normally controlling the operation of one of said plurality of reversed cycle refrigerating machines during operation for heating the air of said enclosure, means.responsive to a first predetermined relatively low temperature of the air to be conditioned for selectively energizing the re- -mainder of said plurality of reversed cycle refrigerating machines for heating the air of said enclosure, auxiliary heating means for said enclosure, and means responsive to a second predetermined relatively lower temperature of the energizing all of said reversed cycle refrigerating machines for continuous operation and connecting said auxiliary heating means for control by said enclosure temperature responsive means.

14. Apparatus for heating the air within an enclosure including a duct, me for circulating the air through said duct, a pair of heat pumps each having `a condenser arranged in said duct for heating the' air circulated therethrough, means responsive to the temperature within said enclosure for controlling the operation of the first oi' said pair of heat pumps, means responsive to a predetermined relatively low temperature of the air to be heated for controlling the operation of the second of said pair oi heat pumps, auxiliresponsive to a ysecond predetermined relatively lower temperature ot the air to be heated for" connecting said heat pumps for continuous heat` ing operation and for connecting said auxiliary heating meansforcontrol by said enclosure temperature responsive means. is

l5. Apparatus for heating the air` within an enclosure comprising `a iirst reirigerating machine including a condenser for heating the air y in said enclosure and -a first and second evaporator outside said enclosure, a second refrigerating machine having a. condenser for heating the air in said enclosure, an evaporator outside said enclosure and a second condenser, afheat storage means operatively associated with said second condenser and adapted to store heatthererom;

means responsive to the temperature within said enclosure for operating said iirst refrigerating machine utilizlngone of saidvevaporators for l 2,241,060 ary heating means for saidenclosure, and means supplying heat to said enclosure, and means ret sponsive to a predetermined temperature of the air being heated for operatively connecting' said other evaporator to said rst refrigerating machine to increase the capacity thereof and for simultaneously operating said second refrigerating machine to supply heat 'to said heat storage means.

16. Apparatus for heating the air within'an enclosure comprising a first refrigerating machine including a condenser for heating vthe air in said enclosure and an evaporator outside said enclosure, a second refrigerating machine having a vcondenser for heating the air in said enclosure, an evaporator outside said enclosure and a second condenser operatively connected to a heat storage means, means responsive to the temperature within said enclosure for controlling the operation of both of said reirlgerating machines,

ature of the air being heated for operating the first refrigerating machine to supply heat to 1'7. Apparatus for heating thel air within an enclosure comprising a :first refrigerating machine including a condenser for heating thev air .in said enclosure and a first and second evaporatoroutside said enclosure, a. second reirigerating machine having a condenser for heating the air in said enclosure; an evaporator outside said enclosure and a second condenser, a heat storage means operatively associated with said second condenser andy adapted to store heat therefrom, means responsive to the temperature within said enclosure for operating said first refrigerating machine utilizing one of said evaporators for supplying heat to said enclosure, means responsive to a predetermined temperature o! the air being heated for 'operatively connecting said other evaporator tc said rst refrigerating machine to increase the capacity thereof and for simultaneously operating ysaid second refrigerating .ma-

chine to supply heat to said heat storage means, and means responsive to a second predetermined temperature of the air being heated for discontinuing the supply of heat from said second condenser to said heat storage means and for operating said second refrigerating machine continuousiy 'to supply heat to said enclosure.

. HAL GIBSON.

means responsive to one predetermined temper- 

